Rails controller create action difference between Model.new and Model.create -

i'm going through few rails 3 , 4 tutorial , come across love insights on:

what difference between model.new , model.create in regards create action. thought use create method in controller saving eg. @post = post.create(params[:post]) looks i'm mistaken. insight appreciated.

create action using post.new

def new   @post = post.new end  def create   @post = post.new(post_params)   @post.save    redirect_to post_path(@post) end  def post_params   params.require(:post).permit(:title, :body) end 

create action using post.create

def new   @post = post.new end  def create   @post = post.create(post_params)   @post.save    redirect_to post_path(@post) end  def post_params   params.require(:post).permit(:title, :body) end 

i have 2 questions

• is rails 4 change?
• is bad practice use @post = post.create(post_params)?

model.new

the following instantiate , initialize post model given params:

@post = post.new(post_params) 

you have run save in order persist instance in database:

@post.save 

model.create

the following instantiate, initialize and save in database post model given params:

@post = post.create(post_params) 

you don't need run save command, built in already.

more informations on new here

more informations on create here